The production of ethylene glycol from other than petroleum sources has been long sought. The dire predictions of significant oil shortages in the future, as well as the cost of producing chemicals from petroleum sources, have resulted in the search for a different low cost source which can be converted into the valuable chemical ethylene glycol. Synthesis gas is one such source which can be produced from non-petroleum sources. Synthesis gas is derived by the combustion of carbonaceous materials including coal, or any organic material, such as hydrocarbons, carbohydrates and the like.
Among the chemicals which may be produced from synthesis gas is methanol. Methanol so produced is a valuable starting material for the manufacture of other useful chemicals.
U.S. Pat. No. 2,153,064 discloses a process for preparing ethylene glycol using methanol as the starting material. In this process methanol is first converted to formaldehyde which is then converted to ethylene glycol.
U.S. Pat. No. 2,152,852 discloses a process for reacting formaldehyde, carbon monoxide and water under high pressure with an acid catalyst to produce hydroxyacetic acid. The hydroxyacetic acid was then reacted with methanol to give the methyl ester of ethylene glycol which was converted to ethylene glycol by catalytic hydrogenation.
French Pat. No. 666,681 discloses a process for manufacturing organic products, such as ethylene glycol, by the oxidation under high pressure (between 100 and 800 kilograms) at a temperature not exceeding 500.degree. C. of raw materials, for example, methanol, in a reaction tube. (A second reaction tube is provided too as a safety tube.)
For a review of the synthesis of ethylene glycol by irradiation of methanol, reference should be made to The Radiolysis of Methanol: Product Yields, Rate Constants, and Spectroscopic Parameters of Intermediates, U.S. Department of Commerce/National Bureau of Standards NSRDS-NBS 54,1975.
U.S. Pat. No. 4,076,758 discloses a process for coupling relatively low-molecular weight primary alcohols to form relatively higher molecular weight vicinal glycols employing a trialkylselyl protecting group on the hydroxyl position of the low molecular weight primary alcohol during the coupling reaction. Of particular interest is the recognition at column 2, line 26 et. seq., "That the direct coupling of methanol undesirably leads to a substantial amount of formaldehyde is seen from the work of Schwetlich et al., Angew. Chem. 72, 779 (1960); and Ladygin and Saraeva, Kinetics and Catalysis, 6, 189-95 (1965) and 7, 832-39 (1966)."